Commonest benign causes:
Need to exclude malignancy.
Investigations
CO poisoning increases Alveolar arterial O2 gradient.
No vasoconstriction in CO poisoning.
Internal capsule strokes are differentiated from cortical strokes by the absence of cortical deficits.
Typical internal capsule stroke syndromes are
Blood supply of the internal capsule:
| Part | Blood supply | Contents | Symptoms |
|---|---|---|---|
| Anterior limb | Mainly LS branches of MCA | Frontopontine fibers Anterior thalamic radiation |
Confusion, agitation, dysarthria |
| Genu | LS branches of MCA | Corticobulbar tracts (i.e descending tracts to the cranial nerve nuclei)ra | Deficiencies of facial expression, swallowing and mastication |
| Posterior limb | LS Branches of MCA Anterior Choroidal artery (branch of ICA) |
1. Descending motor tracts in anterior half, 2. ascending sensory relays in posterior 1/3 |
Pure motor stroke Mixed sensory motor stroke |
[!INFO] Recurrent artery of Huebner
The Recurrent artery of Heubner is a penetrating branch of ACA arising from the A1-A2 junction or proximal A2. It supplies parts of the internal capsule and caudate nucleus. The occlusion of the Recurrent artery of Heubner produces opposite site faciobrachial MONOPARESIS* due to the internal capsule involvement.Source
Occurs due to deficiency of lactase enzyme.
No weight loss or malabsorption
pain, flatulence, borborygmi after ingesting lactose containing meal.
Diagnosis: hydrogen breath test.
Lactose is a disaccharide. Dietary intake decreases from infancy to adulthood.
It's broken down by intestinal lactase to glucose and galactose which are both absorbed by intestinal SGLT-1. Failure to break down lactose reads to passage into the colon where bacterial activity converts it to short chain fatty acids and hydrogen gas. -> symptoms of bloating, flatulence, diarrhoea few hours after ingesting lactose. (?despite the process occuring in the colon)
Soluble end products of bacterial metabolism cause osmotic diarrhoea. Source
It is the most common cause of lactase deficiency, also known as lactase non-persistence. There is a gradual decline in lactase enzyme activity with increasing age. Enzyme activity begins to decline in infancy, and symptoms manifest in adolescence or early adulthood.
[[2021-SBR-November#Coeliac disease|Coeliac Disease]]
Gluconeogensis in Cirrhosis
In cirrhosis, the rate of hepatic gluconeogensis is increased and glycogenolysis is decreased. Source
- Mnemonic: "Back-up" -> upper half of the nucleus has 'back up' innvervation by the contralateral cortex.
[[2020-NOV-BasicSciences#Lactose intolerance|Lactose Intolerance]]